This invention relates generally to intravenous fluid systems, and more particularly, to methods and apparatus for administering intravenous fluids to a patient.
Intravenous (IV) administration of fluids is an integral part of routine patient care, especially for those patients undergoing surgery. During surgery, invariably there is a need for fluids, including blood and saline, to be administered to a patient intravenously. In addition to providing fluids, there is a need to for IV administration of medications. While it is important that the correct fluids and medications are supplied into a vein through a continuous IV flow, delivery of the wrong blood type or medication may be life-threatening to a patient, and as such terminating the intravenous administration of the incorrect fluids and medications requires great immediacy.
At least some known IV systems include two fluid paths which each receive an intake of different fluids that may be supplied to a patient, and a single path for the administration of fluids. Specifically, during surgery the need arises for the administration of saline and/or blood, and as such known IV systems enable both a saline reservoir and a blood reservoir to supply fluids into a common drip chamber. The drip chamber, in combination with a variable resistance controller, allows the fluids to mix and facilitates accurate regulation of the rate of flow of the mixed fluids to the patient. If the patient has an allergic reaction to the blood, or if the blood is incorrectly cross-typed for the patient, tube clamps enable the flow from the blood reservoir to be stopped, such that an increased flow rate may be provided from the saline reservoir. The increased saline flow facilitates diluting the fluid mixture previously supplied to the patient and assists in hydrating the patient.
However, although no additional fluid enters the drip chamber from the blood reservoir when the tube clamp is positioned, any blood remaining in the IV system downstream from the tube clamp is still supplied to the patient, along with the increased flow rate of saline. Depending on the patient's reaction, the additional amount of incorrect fluid supplied to the patient may be life threatening to the patient. Accordingly, at least some known emergency procedures mandate that the IV system be uncoupled from the patient and either be flushed clean, or replaced with a new IV system. While such an emergency procedure ensures that the additional incorrect fluid is not supplied to the patient, replacing the IV system may be a time consuming and life-threatening event.